As Brandon Lincoln Woodard walked near Columbus Circle and the southwest end of New York's Central Park looking around and checking his phone, his killer lay in wait.

The killer had been in the area for at least 40 minutes Monday afternoon, ABC News has learned. And the car in which the killer fled was parked about 20 yards from where the shot was fired into the back of Woodard's head from very close range.

"When I heard the shot, I turned around and saw him dropping on the floor," witness David Mirambeau told ABC News station WABC-TV.

Just before he was shot, Woodard, 31, of Los Angeles, turned "instinctively almost," then turned back to his portable electronic device, police told ABC News.

"As he walks up to the victim the victim turns, but he makes nothing of it," a police source said. "He is looking at his phone or iPod as he is walking. The shooter gets right behind him.

"It is one shot right in the back of the head. It is a hit, no question about it."

Witnesses say the gunman then calmly got into the passenger's side of a waiting silver-colored Lincoln sedan and took off.

Police are reviewing nearby security camera footage for clues to who the gunman might be.

Police in New York and Los Angeles told ABC News that they were running down leads that linked Woodard to L.A.'s entertainment industry, where they said he may have worked as a lawyer.

Friends described Woodard as a man with "an infectious smile," a "wonderful guy, lively, [the] life of the party," and, "very smart, very much a part of the fiber of African American culture in Los Angeles." Friends also say Woodward was the father of a 4-year-old daughter.

Sources tell ABC News that Woodard was arrested in 2009 in connection with a robbery in California.

Woodard was raised in Los Angeles' Ladera Heights neighborhood and attended the private Campbell Hall High School, they said. He then attended college and then law school at Loyola Marymount College in Los Angeles, law enforcement sources and friends said.

The victim's father, Jessie Lincoln Woodard, reached by telephone, confirmed that his son graduated from Loyola with a degree in business administration in 2003 and later attended law school.

Jessie Lincoln Woodard divorced Brandon Lincoln Woodard's mother in 1982 and said that the last time he saw his son was in 1998 at his high school graduation.

He learned of his son's shooting when he was contacted by the NYPD.

ABC News' Laurie Bossi and Michael S. James contributed to this report.